Current quality assessment techniques addressing problems in diagnostic processes suffer from lack of a coherent theoretical and methodological framework. Current assessment techniques and research technique addressing similar issues will be placed in a common analytic framework and compared. Formal group process and decision theory techniques will be used to generate pilot criteria sets utilizing this framework. Specifically theoretical framework for conceptualizing problems in diagnostic processes will be elaborated. The range of research and assessment techniques capable of addressing each type of problem will be identified and compared. Formal decision theory and group process techniques will be adapted for the criteria generation process to ensure systematic consideration of potential diagnostic problems. The framework and techniques will be operationally tested by having independent groups of academic and non-academic clinicians develop criteria sets for common diagnostic problems. The study designs so produced will be compared with each other and with other published assessment criteria. A general model for this study is the recent work on outcome techniques (Brook et.al, 1976) The guiding conception is that quality assessment can be fruitfully seen as a branch of evaluative research.